Water streams in from the bays and Atlantic Ocean, sweeping over the Delaware beach area — no mercy for the vacation homes dotting the shore.

For coastal residents, the floods are part of life. Christine Gulbronson lives in Fenwick Island but works as an office manager at Hammerheads, a restaurant in Dewey Beach.

"When they have to shut down Route 1, my only way around is through the back roads," she said.

During a nor'easter, when the ocean reaches over the sand dunes and spreads onto the highway, her commute gets stretched from 20 minutes to an hour. 

"It obviously affects people from the south getting north to our two restaurants," Gulbronson said. 

Hammerheads has had to close a couple of times, not because of property damage, but due to the closure of flood-prone roads.

And that's just one example for the busy tourism area.

“Delaware is a microcosm for a really interesting trend coastwide,” said Chris Bason, the executive director of Center for the Inland Bays. “People are moving to the coast, to the low-lying areas, while at the same time, the level of the sea is rising faster than it has in the past 1,000 years.”

The First State is particularly vulnerable, with its flat topography, low elevation and significant development in coastal areas dominated by tourism, according to climate scientist John Callahan of Delaware Geological Survey.

“The Mid-Atlantic coast is a hotspot for sea level rise,” added Bason, who has been in the area since 2004. “We’re where the (elevation of the ocean) is a little bit higher, which poses special concerns for us. Flooding is one of them.”

With flooding, road closures and bright orange detours signal more driving, more traffic. Cars gurgle by, their tires spewing up water like tiny Ferris wheels. 

Elected officials urge people along the coast to move inland.

In the past 100 years, the rate of sea level rise at the Lewes tidal gauge was about 3.42 millimeters per year, but looking at the past 25 years, the annual rate increased to 5.5 millimeters, according to the National Oceanic Atmospheric Administration.

Increased development, which causes land compression, puts more stress on Delaware’s water cycle, according to Gilliam.

In the last 50 years, marshland along Route 1 south lost an average of 4.3 acres annually due to a combination of sea level rise, human activity and wave energy, according to DelDOT.

Like clockwork, Delaware has systems in place to prepare for and combat the resulting floods.

In mid-December, the Department of Transportation laid out an 80-day project to resurface 4.3 miles of roadway on Route 1 in Dewey Beach, starting in the spring.

Part of that project includes a 2,000-foot flood-prone patch of roadway between New Road and Key Box Road that will be raised an additional 4 inches.

“The 4 inches was determined to be an acceptable amount,” said Charles McLeod, the Director of Community Relations at DelDOT. “It’s the sweet spot for seeing the least amount of sinking or compression on the roadway.”

Bason’s gut tells him it’s a lot more tenuous a situation than most people would think driving up and down Route 1. He's noticed an increase in road closures and flooding in the past five years.

“It’s getting to the point where the road is flooding or just about flooding even when the weather is clear," Bason said.

Planning for the future

Coastal flooding in Delaware has a thousand fathers.

One of them is the Indian River Inlet, where jetties stick out perpendicular to the coast, trapping sand on the south side. This causes a sand deficit on beaches north of the inlet, and that process weakens the dune system, according to Bason.

“That’s why DelDOT is moving quickly to find a solution,” said Bason. “This is a much-needed project. It’s not a long-term solution but it’s very much needed.”

The project is part of a concentrated effort by DelDOT to improve the peninsula’s infrastructure as sea levels continue to rise at an accelerated rate.

“We’re basically planning for the future,” DelDOT Secretary Jennifer Cohan said.

DelDOT group engineer LaTonya Gilliam said coastal Route 1 is one of the biggest issues the agency faces, in regards to flooding.

“Every time there is a nor’easter or a hurricane, it greatly affects us,” Gilliam said. “Storm events are more frequent and more intense so we are seeing some of our roads along the shoreline erode a lot more.”

As sea levels rise due to factors like climate change, flooding will increasingly affect large swaths of land that support entire economies. In particular, beach erosion will take away natural protection for public infrastructure, commercial buildings and private property.

While climate change is a natural process of warming and cooling, global industrialization activities like burning fossil fuels and deforestation emit greenhouse gases. Those gases hold heat, a good deal of which is stored in the ocean. 

Combine that with other long-term factors like melting land-based ice sheets, a weakening gravitational force of Greenland and Antarctic ice sheets as they melt, and a 17,000-year-old process called glacial isostatic adjustment — which causes land subsidence — and you have a recipe for accelerated sea level rise, according to Callahan. 

The resulting shoreline erosion causes major ecological damage, which affects the tourism-driven economies of resort areas.

In Sussex County, up to 56 percent of state park lands and 99 percent of tidal saltwater wetlands are projected to be inundated by 2100, depending on how much sea levels rise. Between 79 and 357 miles of road are estimated to meet the same fate, according to 2012 projections by Delaware Department of Natural Resources and Environmental Control. 

Gilliam said the Route 1 project is a good fix in the short-term. DelDOT is focused on preparedness: It is helping residents understand tidal events, and is even working with a state climatologist to develop an app for residents to monitor the tide.

It's also using grant funds from the Climate Framework for Delaware, which requires state agencies to address energy and climate impacts.

DelDOT was tasked with looking at ways to manage storm water runoff and combat coastal erosion.

Gilliam is part of the Coastal Corridor working group, which works with elected officials along the coasts — including Dewey Beach, Bethany, Fenwick Island and Lewes — to help towns define resilience on their turf and plan to make the corridor as a whole more resilient to climate change.

Beach replenishment is costly, so DelDOT is taking protective measures, including investing in green infrastructure like “living levies,” which help naturally restore and stabilize dune systems.

The Route 1 project is the detail, the necessary solution for current road improvements. But the big question, Bason said, is about investment in prevention — policies that keep people and infrastructure away from the coast.

“Most of the growth has been near the inland bays and on the water — those are vulnerable areas,” Bason said.

State transportation officials elevated flood-prone Del. 54, just west of Fenwick Island, near where Gulbronson lives.

"It's made a tremendous difference," she said.